Ecological arrangement of floro-faunistic heterogeneity of northern Eurasia

In the previous articles on the faunistic and floristic zoning of the northern Eurasia the results were summed up. At first, in was done on all classes of terrestrial vertebrate animals separately, then on fishes and cyclostomes and after that on all these groups together (Ravkin, Bogomolova, Tsybulin, 2015a) as well as on invertebrate animals and flora of woody plants (Ravkin et. al., 2014, 2015b). The main aim of this analysis is a complex biotic zoning apart from comparing the variants of the local zoning produced on the same basis and using the same approaches and computing instruments. The analysis of biota as a whole is rather difficult, as the number of even vascular plants species and, consequently, their similarity due to flora can be significantly greater than that of invertebrate animals. Moreover, the number of species and diversity of invertebrate animals is greater than that of vertebrate ones. For this reason in joining species lists the regularities of flora heterogeneity may suppress the specificity of fauna variability in the case of their divergence. It seems that at first it is necessary to carry out the local zoning on the certain classes of terrestrial animals, and then on the whole group of the animals which fauna is described comprehensively. The data on the distribution of invertebrate animals are scarce, therefore, it is more reasonable to analyze a reference sampling of well studied species; for example, a part of beetle species. For that, we used the data on the species of Nemonichids, bark beetles, Anthribus and leaf-roller weevils (Ravkin et al., 2014; Ravkin et al., 2915). As a reference floristic group some woody plants were taken. These three samplings were conventionally considered as equal ranking. Thereto matrixes calculated for them were averaged out. This approach was effective in simultaneous analyzing soils, mort-, phito- and zoomass the values of which significantly differ (Ravkin et al., 2011). Materials, methods and approaches to these investigations have been presented in the papers listed in the Introduction. The territory of the northern Eurasia (within the confines of the USSR, 1991) was divided into 597 regions, as it was in database “Biodat”(http:www.biodat.ru) As a result, it can be stated that there are four latitudinal floristic faunistic zones more or less corresponding to polar desert, tundra, open boreal woodland and latitudinal zone from the northern taiga to the northern (meadow) stepper. In addition, there are at least two wedge inclusions of southern flora and fauna: Mediterranian ones – to the Caucasus and Crimea; and in the East in the southeastern coastal Pacific sub-region, those of Japanese and Chinese flora and fauna – to the Ussuriland, Sakhalin island and the Kurils. Such a penetration is caused by the heating effect of the Mediterranean in the West and by monsoons in the East. Kazakhstani and Central Asian sub-region can be considered as a wedge inclusion of semi-desert and desert conditions from the South and appropriate specificity of flora and fauna. The heating effect of the Atlantic results in diagonal boundary displacement from the Southwest to the Southeast, and that of the Pacific – from the Northeast to the Southwest. At that, the deviation from this trend is clearly seen in northern coast of the Sea of Okhotsk due to the effect of mountain ranges of Eastern Siberia and Far East. In the spatial typological structure and ecological organization of heterogeneity of flora and fauna, two main trends can be retraced. The first one exhibits the latitudinal character of changes (from polar deserts to hot ones across tundra, open boreal woodland, taiga, woods, forest-steppe and steppe). The second trend has a longitudinal enclave spreading such as Crimean and Caucasian sub-region in the Southwest as well as the northern and southern Pacific coastal sub-regions in the East. According to the classification, there are five correlated factors influencing the variability of fauna and flora. All of the factors are of integrated character, but their difference may be restricted by heat supply. It can be connected with dispersion of fauna and flora matrix similarity coefficients by 62%. Zonality and provinciality take into account 50% and 20%, respectively. Island effect and mountings determine a significantly less part of heterogenity due to relatively small area of islands and mountain group. All these factors can explain 73% similarity dispersion, that is the excess in heat supply due to environmental factors is 10% dispersion. Classificational and structural regimens, as inseparable combination of factors, determine 79% dispersion and add 13% to the explanation of heat supply. In general, the results of cluster analysis of the heterogeneity of fauna and flora in northern Eurasia confirm with the concept on the spatial variability of flora and fauna in this region presented earlier. However, nonparametric statistical methods enable not only to confirm some previous conclusions, but to reject some of them as well as to show the low informative value of the number of common concepts, for example, about the significance of the Urals and the Yenisei as borders in fauna and flora heterogeneity. In the distinguished sub-regions a number of regions belong to a greater of lesser extent to certain zones and sub-zones (45 – 100% in each taxon, although their composition never coincides completely with zonal and sub-zonal one. Due to the difference in tolerance of animals and plants the boundary lines run out on the basis of plants do not always coincide with floristic and faunistic ones. At that, some diagonal displacements are retraced in relation to the natural zone boundaries; they are associated with various reactions of different species to the heat supply of the territory. The received results coincide with those received by climatic zoning to a greater extent than by complex physical geographic one